Решите данный пример

По действиям:

1) $\frac{3x}{(x-y)( x^{2} +xy+ y^{2} )} * \frac{( x^{2} +xy+ y^{2} )}{x+y} = \frac{3x}{(x-y)(x+y)}$

2) $\frac{3}{x-y} + \frac{3x}{(x-y)(x+y)} = \frac{3x+3y+3x}{(x-y)(x+y)} = \frac{6x+3y}{(x-y)(x+y)}$

3) $\frac{3(2x+y)}{(x-y)(x+y)} * \frac{ (x+y)^{2} }{(2x+y)} = \frac{3(x+y)}{(x-y)}$

4) $\frac{3(x+y)}{(x-y)} * \frac{3}{(x+y)} = \frac{9}{(x-y)}$

Ответ. $\frac{9}{(x-y)}$